Lubricant



Patented Apr. 6, 1943 LUBRICANT Clarence M. Loane, Hammond, Ind., and James W. Gaynor, Chicago, 111., assignors to Standard Oil Company, Chicago,

Indiana 11]., a corporation of No Drawing. Application November 27, 1941, Serial No. 420,704

28 Claims.

The present invention relates to a method of' I substantially inhibiting the formation and/or deposition of gums, resins, and varnish-like materials in internal combustion engines and upon and about the valves and rings of such engines.

This application is a continuation-in-part of our co-pending applications Serial No. 384,940 and Serial No. 384,941, filed March 24, 1941.

Many oils are not well suited for the lubrication of internal combustion engines, particularly engines of the Diesel type and of other types operating under similar severe operating conditions, because under such severe operating conditions they are susceptible to deterioration which results in the development of carbonaceous and/or resinous or similar varnish-like deposits reagent. Other metal constituents such as a heavy'metal constituent may be introduced into the neutralized product by reacting the same with a salt of the desired heavy metal.

The term neutralized phosphorus sulfide-hydrocarbon reaction product as used herein means a phosphorus sulfide-hydrocarbon reaction' product having at least about 1% of its titratable acidity reduced by the reaction with a basic rein the engine and on and about" the valves and rings thereof. These objectionable deposits often result in such sticking of the valves'and rings as to interfere seriously with the operation of the engine. It is an object of the present invention to provide an additive for lubricating oils which will materially inhibit the formation of carbonaceous deposits and/or resinous varnish-like materials in internal combustion engines and on and about the valves, pistons and rings of the engine.

It is a further object of the present invention to provide a method of lubricating internal combustion engines operating under severe conditions without the formation of substantial amounts of carbonaceous and varnish-like materials on the valves, pistons and piston rings of the engine.

Other objects and advantages of the invention will become apparent as the description thereof proceeds.

We have discovered that the foregoing objects may be attained by lubricating internal combustion engines with a lubricating oil, preferably a mineral lubricating oil, containing small amounts, namely, from about 0.001% to about 10.0%, preferably from about 0.61% to about 3.0% of a reaction product of a hydrocarbon and a sulfide of phosphorus. The sulfide of phosphorus may be P283, P235, P433, P457, 01 other phosphorus sulfide, and preferably phosphorus pentasulfide, P235.

The phosphorus sulfide-hydrocarbon reaction product normally shows a titratable acidity. This titratable acidity is neutralized when the reaction product is treated with a basic reagent. The phosphorus sulfide-hydrocarbon reaction product when neutralized with a basic reagent containing a metal constituent is characterized by the presagent, and includes the neutralized phosphorus sulfide-hydrocarbon reaction products containing a metal constituent resulting from said neutralization or resulting from the reaction of a heavy metal salt with the phosphorus sulfide-hydrocarbon reaction product treated with a basic reagent.

The neutralized phosphorus sulfide-hydrocarbon reaction product may be obtained by adding to the reaction product a suitable basic compound such as a hydroxide, carbonate, or an oxide of an alkaline earth metal or of an alkali metal, preferably potassium hydroxide or sodium hydroxide. Other basic reagents may be used such as, for example, ammonia, or alkyl or aryl substituted ammonia, such as amines. As aforesaid, when the phosphorus sulfide-hydrocarbon reaction product is neutralized with a basic compound containing a metal constituent the neutralized reaction product is characterized by the presence of the metal constituent of such basic reagent. N eutralized reaction products containing a heavy metal constituent such as, for example, tin, titanium, aluminum, chromium, cobalt, iron and the like may be obtained by reacting a salt of the desired heavy metal with the phosphorus sulfide-hydrocarbon reaction product which has been treated with a basic reagent.

It will be understood that when the neutralization is accomplished with a polyvalent basic material, such as lime, a product having excess basicity may be obtained.

The hydrocarbon reactant is preferably a hydrocarbon compound having a molecular weight greater than about 150 and preferably a molecular weight greater than about 300. The hydrocarbons may be paraflins, olefins or olefin polymers, aromatics, or alkyl aromatics, cyclic aliphatics, petroleum fractions such as lubricating oil fractions, petrolatums, waxes, --cracked cycle stocks, or condensation products of petroleum once or retention of the metal constituent of the fractions, solvent extracts of petroleum fractions, etc.

Essentially paraflinic hydrocarbons such as bright stock residuums, lubricating oil distillates, petrolatums, or paraflln waxes may be used. We may also employ the condensation products of metal hydroxide or oxide.

i'owax by heating the same for a any of the foregoing hydrocarbons, usually through first halogenating the hydrocarbons, with aromatic hydrocarbons in the presence of anhydrous inorganic halides, such as aluminum chloride, zinc chloride, boron fluoride and the like.

As examples of high molecular weight olefinic hydrocarbons which we may employ as reactants are cetene (C16), cerotene (C26), melene (Can), and mixed high molecular weight alkenes obtained by cracking petroleum oils.

Other preferred olefins suitable for the preparation of the hereindescribed phosphorus sulfide reaction products are olefins having at least 20 carbon atoms in the molecule of which. from about 12 carbon atoms to about 18 carbon atoms, and preferably at least carbon atoms, are in a long chain. Such olefins can be obtained by the dehydrogenation of parafiins, such as by the cracking of paraffin waxes, or by the dehalogenation of alkyl halides, preferably long chain alkyl halides, particularly halogenated paraffin waxes.

The olefins obtained by dehalogenation of long chain alkyl halides are preferably. those obtained by dehalogenation of monohalogenated waxes, such as, for example, those obtained by dechlorination of monochlor paraffin wax. The alkyl halides are decomposed to yield olefins according to the reaction in which n is a whole number, preferably 20 or more, and X is an halogen. We prefer to employ paraffin waxes having at least about 20 carbon atoms per molecule, and melting points upwards from about 90 F. and preferably within the range of from about 120 F. to about 140 F.

To obtain the halogenated paraffin wax, for example, chlorinated paraflin wax, we introduce chlorine into the wax, maintained in a molten state, until the wax has a chlorine content of from about 8% to about 15%. The chlorinated wax product is a mixture of unchlorinated wax, monochlor wax and polychlor wax. This chlorinated product may be used as such, but 'it is advantageous to use the substantially monochlor wax fraction. The monochlor wax fraction can be segregated from the unchlorinated wax and the polychlor wax fractions by taking advantage of the differences in the melting points of the various fractions, since the melting point of the wax varies with the extent of chlorination: i. e. the melting point of the unchlorinated wax is greater than that of the monochlor wax, and the melting point of the latter is greater than that of the polychlor wax. Thus, the monochlor paraffin wax can be separated from the unehlorinated and the polychlor wax fractions by means such as sweating, fractional distillation, solvent extraction, solvent precipitation, and fractional crystallization.

The high molecular weight olefins are obtained by removing the halogen as hydrogen halide from the halogenated paraffin wax. For example, the corresponding olefin is obtained from the monochlor parafiin wax by removing the chlorine from the latter as hydrogen chloride. The monochlor wax can be dechlorinated by heating to a temperature of from about 200 F. to about 600 F. in the presence of a dechlorinating agent such as an alkali metal hydroxide or an alkaline earth Other alkaline inorganic or organic materials can also be used. The chlorine can also be removed from the chloprolonged period phosphorus sulfide in the reaction.

in the absence of any dechlorinating agent. After the dehalogenation has been completed the olefin so obtained can be further purified by removing the dehalogenating agent by means of filtration or by other suitable means.

We may also employ olefin polymers having molecular weights above and preferably above 300. As olefinic starting materials for the production of such polymers, we may employ the individual olefins themselves, mixtures of olefins or mixtures of olefins and non-olefinic compounds. For example, the olefinic starting material may be butylene, amylenes, refinery gases containing normally gaseous olefins and cracked distillates or other relatively low-boiling hydrocarbon mixtures containing normally liquid olefins and mixtures of normally liquid olefins, containing substantial amounts of dissolved normally gaseous olefins.

The polymers referred to above may be those obtained by polymerizing olefinic hydrocarbons in the presence of catalysts such as sulfuric acid, phosphoric acid, or aluminum chloride, zinc chloride, boron .fluoride and other catalysts of the Friedel-Crafts type. For example, we may employ the polymers resulting from the treatment of mono-olefins preferably iso-mono-olefins such as isobutylene and isoamylene and/or the copolymers obtained by the polymerization of hydrocarbon mixtures containing low molecular weight iso-olefins and normal olefins, preferably those of less than six carbon atoms.

We may also employ as the starting material the polymer or synthetic lubricating oil obtained by polymerizing unsaturated hydrocarbons resulting from the vapor phase cracking of paraffin waxes in the presence of aluminum chloride which is fully described in United States Patents Nos. 1,995,260, 1,970,002 and 2,091,398. Still another type of olefin polymer which may be employed is the polymer resulting from the treatment of vapor phase cracked gasoline and/or gasoline fractions with sulfuric acid or solid absorbents such as fullers earth whereby unsaturated polymerized hydrocarbons are removed. Also contemplated within the scope of our invention is the treatment withphosphorus sulfide of the polymers resulting from the voltolization of hydrocarbons as described, for example,- in United States Patents Nos. 2,197,768 and 2,191,787.

Also contemplated within the scope of the present invention are the reaction products of a phosphorus sulfide with an aromatic hydrocarbon such as, for example, benzene, naphthalene, toluene, xylene, diphenyl and the like, or with an alkylated aromatic hydrocarbon such as, for example, benzene having an alkyl substituent having at least four carbon atoms and preferably at least eight carbon atoms such as a long chain parafiin Wax.

The additive employed in the present invention is the neutralized reaction product obtained by reacting one or more of the hereindescribed hydrocarbons with a phosphorus sulfide, preferably phosphorus pentasulfide. The phosphorus sulfide-hydrocarbon reaction product may be readily obtained by reacting the phosphorus sulfide, for example, P2S5, with the hydrocarbon at a temperature of from about 200 F. to about 500 F. and preferably from about 200- F. to about 400 F. using from about-1% to about 50% and preferably from about 5% to about 25% 6f the It is advantageous to maintain a non-oxidizing atmosphere,

such as, for example, an atmosphere of nitrogen, above the reaction mixture. Usually it is preferable to use an amount of the phosphorus sulfide that will completely reactwith the hydrocarbon so that no further purification becomes necessary. However, excess phosphorus sulfide may be used and separated from the product after heating is discontinued by filtering or by diluting with a solvent such as hexane, filtering, and subsequently distilling off the solvent. If desired, the reaction product may be further treated by blowing with steam at an elevated temperature of from about 200 F. to about 600 F. to improve the odor thereof.

The neutralized phosphorus sulfide-hydrocarbon reaction product may then be prepared by reacting the above phosphorus sulfide-hydrocarbon reaction product with a hydroxide, an oxide or a carbonate of an alkali metal or an alkaline earth metal, and preferably with potassium hydroxide or sodium hydroxide. This reaction may be carried out, preferably in a non-oxidizing atmosphere, by contacting the phosphorus sulfidehydrocarbon reaction product either as such or dissolved in a suitable solvent such as naphtha with a solution of the metal compound, for example, potassium hydroxide or sodium hydroxide dissolved in alcohol. As an alternative method the phosphorus sulfide-hydrocarbon reaction product may be treated with solid alkaline compounds, such as KOH, NaOI-I, NaaCOz, NaHCOa. KHCOa, K2CO3, CaO, preferably at an elevated temperature of from about 100 F. to about 400 F. Neutralized reaction products containing a heavy metal constituent may be prepared by reacting the neutralized reaction product with a salt of the desired heavy metal.

Th phosphorus sulfide-hydrocarbon reaction product or the neutralized reaction product may be treated with halogen to introduce a halogen constituent.

The neutralized phosphorus su fide-hydrocarbon reaction product may be used in lubricating oils alone, or in combination with the non-neutralized phosphorus sulfide-hydrocarbon reaction product. A much improved lubricant is obtained when a small amount, for example, from about 0.001% to about 10.0% and preferably from about 0.01% to about 3.0% of the neutralized phosphorus sulfide-hydrocarbon reaction product is added to a lubricating oil alone or in combination with about 0.001% to about 10.0% and preferably from about 0.01% to about 3.0% of the non-neutralized phosphorus sulfide-hydrocarbon reaction product.

As a specific embodiment of our invention the following examples are given by way of illustration and are not intended as a limitation of the invention.

EXAMPLE I A polymer obtained by treating a hydrocarbon mixture containing about 10% to about 25% isobutylene with boron fluoride at a temperature of about 32 F. was distilled to a bottoms having a Saybolt Universal viscosity at 210 F. of about 3000 seconds. These bottoms were then reacted with 10% phosphorus pentasulfide at a temperature of 370 F. to 390 F. for five hours, and then blown with nitrogen for an additional five hours within the same temperature range. This reaction product had a sulfur content of about 6% and a phosphorus content of about 3%. A portion of this reaction product was then diluted with 5 volumes of hexane and thoroughly agitatedwith 3 volumes of 5% KOH in 70% al h l Th 75 product, after the hexane layer was separated and the hexane removed by distillation, was a neutralized Pzss-isobutylene polymer reaction product containing potassium as a metal constituent.

EXAMPLE II A portion of the above non-neutralized PzSspolymer reaction product of Example I was treated in the following manner: To 300 grams of the reaction product, 9 grams of dry KOH were added at a temperature of 200 F. The temperature was then increased to 340 F., maintained at 340 F.- 350" F. for five hours, and then heated at this temperature for eighteen more hours while bubbling nitrogen through the mixture. The final product containing potassium was neutralized to a lesser degree than the product of Example I and had an acidity of 105mg. KOH per gram of product.

The neutralized products may be further improved as to odor by blowing the same at an elevated temperature with steam or nitrogen.

EXAMPLE III Paraffin wax having a melting point of 132 F. was heated to -200 F. and While maintained within this temperature range was treated with chlorine gas until the chlorinated wax contained about 14% chlorine by weight.

The chlorinated wax so obtained was then dechlorinated by heating the same for 5 hours at about 560 F. with 100% excess calcium oxide.

The dechlorinated wax was then reacted with 10% phosphorus pentasulfide at a temperature of 380-400 F. for 4 hours, and the reaction product then diluted with a high grade 20 SAE motor oil to a 50% solution.

The diluted reaction product was then neutralized by treatment with 5% KOH, using a 50% aqueous solution of KOH, at a temperature of 400 F. for 2 hours.

While we prefer to employ the neutralized reaction product, the unneutralized reaction product can also be successfully used as a lubricant additive.

Samples of an SAE 20 lubricating oil containing 1) /2% of the PzSs-isobutylene polymer reaction product of Example I and A.;% of the neutralized PzSs-isobutylene polymer reaction prodduct of Example I (2) 1% of the neutralized product of Example II, (3) 1% of the neutralized product of Example I, and (4) 2% of the neutralized Pass-dechlorinated chlorwax reaction product of Exampl III were subjected to the hereinafter described tests along with known commercial oils to determine the relative effectiveness of our improved lubricant.

The following oils were tested:

Oil A is a high grade SAE 20 motor oil from MC crude oil. Oil B is a high grade heavy duty bus and truck motor 011.

Oil C is a high grade SAE 20 Pennsylvania motor oil.

Oil D is oil A+/2% of the non-neutralized P285- isobutylene polymer reaction product of Example I+1/2% of the neutralized Pzsa-isobutylone polymer reaction product of Example I. Oil E is oil +l% of the neutralized Pass-isobutylene polymer reaction product of Example II.

' Oil F is oil A+l% of the neutralized Pass-isobutylene polymer reaction product of Example I.

011 G is oil. A+2% of the neutralized Pass-dechlorinated chlorwax reaction product of Example III.

In the first test the oils-were subjected to an accelerated engine test made in a standard six cylinder automobile motor operating for sixty hours at 35 B. H. P. and 3000 R. P. M. and an oil sump temperature of about 285 F. At the end of the test period the engine was dismantled and given a visual engine rating. In this visual rating a rating of 10 means that the engine had the appearance of the engine at the start of the test,

while a rating of 1 means that the engine after the test showed very extensive depositions of varnish and sludge. Engines having appearances between these extremes are given intermediate rating values. An engine lubricated with a good conventional motor oil, for a sixty hour period usually merits a visual rating of about 5. The data obtained are tabulated in Table I.

TABLE I ACCELERATED ENGINE TEs'r Visual engine rating at end of 60 hours Ring Under Piston Sludge Overall 011 belt crown v varnish deposits carbon carbon lfltllll.

4. 9 4 4 5. 4 5. l 5. 5 7 ii (i (i. 0 8 7 8 8- 7. 8 ll) l0 10 H- 0. 8 9. 3 9. 5 l0 8 9. 2 .l 9. 7 9. 5 9. 7 9. 5 9. 6

TABLE II Oil deterioration at end of 60 hour engine test Acidity Per cent Sludge Viscosity 1 011 mg. carbon mg./l0 g.

were KOH/g. oil residue m1 9. 7 2. 5 315 2. 4 1. 31 162 15.1 3. so a 2. 0 0. 51 a I Saybolt Universal viscosity at 210 F.

The above data show the marked stabilityof our improved lubricant.

In a second test 250 cc. of the oil to be tested is heated at 330 F.-332 F. in a 500 cc. glass beaker in the presence of five square inches' of copper and ten square inches of iron. Four glass rods of six millimeter diameter are suspended in the oil which is stirred at about 1300 R. P. M. with a glass stirrer having a 40 blade pitch. At stated intervals oil samples are taken and sludge, acidity and viscosity-values determined. The glass rods are also inspected for evidence of varnish formation thereon. Varnish values are based on a visual rating in which a glass rod free of any varnish is given a rating of 10, while a badly coated rod is given a rating of 1. Rods having appearances between these extremes are given intermediate values. The data obtained are tabulated in Table III.

TABLE III S'rnmnw Oxnmrrox 'las'r (1.300 R. P. M. 330 F., metallic iron and copper catalysts) I Rating scale: 10=no deposit.

, l=very heavy deposit. SayboltgUniversal viscosity at F.

These data show the superiority of oils D, E, F and G over the high grade well known commercial motor oils.

The reaction product per se made according to this invention, and the method of preparing same, are claimed in a copending application.

While we have described the use of our additives in lubricating oils, our invention is not limited to such use, since these reaction products may be employed in other petroleum products such as insulating oils, white oils, greases, waxes and the like to increase the resistance thereof to oxidation and sludging, to inhibit the tendency thereof to corrode metals, and to deactivate metal surfaces which the above products may contact.

While we have described preferred embodiments of our invention, other modifications thereof may be made without departing from the scope and spirit of the invention, and we do not wish to limit our invention to the examples set. forth herein except insofar as the'same is defined by the following claims.

We claim:

1. A lubricant containing hydrocarbon oil and a minor amount of neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a long chain olefin hydrocarbon of at least about 12 carbon atoms.

2. A lubricant containing hydrocarbon oil and a minor amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a long chain mono-olefin hydrocarbon of at least about 12 carbon atoms.

3. A lubricant containing hydrocarbon oil and a minor amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefin hydrocarbon having at least about 20 carbon atoms in the molecule.

4. A lubricant containing hydrocarbon oil and a minor amount of a neutralized phosphorus and sulfur containing reaction product of a phosphorus sulfide and a mono-olefin hydrocarbon having at least about 20 carbon atoms in the molecule.

5. A lubricant containing hydrocarbon oil and a minor amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefin hydrocarbon having in the molecule at least about 20 carbon atoms, of which at least 12 carbon atoms are in a straight chain.

6. A lubricant containing hydrocarbon oil and a minor amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a mono-olefin hydrocarbonhaving in the molecule at least about 20 carbon atoms, of which at least carbon atoms are in a straight chain.

7. A lubricant as described in claim 5 in which the neutralzed reaction product contains potas- 5mm.

8. A lubricant containing hydrocarbon oil and a minor amount of the metal-containing neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefin hydrocarbon having in the molecule, at least about carbon atoms said olefin hydrocarbon being obtained by dehalogenating an alkyl halide.

9. A lubricant containing a minor amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefin hydrocarbon obtained by dehalogenating a halogenated paraflin Wax, said paraffin wax having a melting point of at least about F.

'10. A lubricant containing hydrocarbon oil and a minor amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a mono-olefin hydrocarbon obtained by dehalogenating a halogenated paraffin wax, said parafiin wax having a melting point within the range of from about F. to about 11. A lubricant containing hydrocarbon oil and a small amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefin hydrocarbon obtained by dechlorinating a chlorinated paraflin wax containing about 14% chlorine by weight, said paraflin wax having a melting point within the range of from about 120 F. to about 140 F.

12. A lubricant asdescribed in claim 11 in which the phosphorus sulfide is phosphorus pentasulfide.

13. A lubricant as described in claim 11 in which the neutralized reaction product contains potassium.

14. A lubricant as described in claim 11 in which the neutralized reaction product contains sodium.

15. A lubricant as described in claim 11 in which the neutralized reaction product contains calcium.

- 16. A new composition of matter containing a petroleum fraction and a small amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefin hydrocarbon having at least about 20 carbon atoms in the molecule.

17. A new composition of matter containing a petroleum fraction and a small amount of the neutralized phosphorus and sulfur-containing reaction product of the phosphorus sulfide and an olefin hydrocarbon having at least about 20 carbon atoms in the molecule obtained by dehalogenated halogenated petroleum wax.

18. A lubricant containing a hydrocarbon oil and a minor amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a long-chain olefin hydrocarbon of at least about 12 carbon atoms, said neutralized reaction product containing a metal constituent.

19. A lubricant containing a hydrocarbon oil and a minor amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a long-chain olefin hydrocarbon of at least about 12 carbon atoms, said neutralized reaction product containing potassium.

20. A lubricant containing a hydrocarbon oil and a minor amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a long-chain olefin hydrocar bon of at least about 12 carbon atoms, said neutralized reaction product containing sodium.

21. A lubricant containing a hydrocarbon oil and a minor amount of a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a long-chain olefin hydrocarbon of at least about 12 carbon atoms, said neutralized reaction product containing calcium.

22. A new composition of matter comprising a hydrocarbon oil and a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a long-chain olefin hy'drocarbon of at least about 12 carbon atoms.

23. A new composition of matter comprising a hydrocarbon oil and a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and an olefin hydrocarbon having at least about 20 carbon atoms in the molecule.

24. A new composition of matter as described in claim 23 in which the neutralized reaction product contains a metal constituent.

25. A new composition of matter as describedv in claim 23 in which the neutralized reaction product contains potassium.

26. A new composition of matter as described in claim 23 in which the neutralized reaction product contains sodium.

27. Anew composition of matter as described in claim 23 in which the neutralized reaction product contains calcium.

28. A new composition of matter comprising a hydrocarbon oil and a neutralized phosphorus and sulfur-containing reaction product of a phosphorus sulfide and a mono-olefin hydrocarbon having at least about 20 carbon atoms in the molecule.

CLARENCE M. LOANE. JAMES W. GAYNOR. 

